On Tue 21-09-21 20:12:08, Vishnu Rangayyan wrote: > > > On 9/21/21 5:59 AM, Michal Hocko wrote: [...] > > Why > > is fsync helping at all? Why do we need a new sysctl to address the > > problem and how does it help to prevent the memcg OOM. Also why is this > > a problem in the first place. > The simple intent is to allow the core dumping to succeed in low memory > situations where the dump_emit doesn't tip over the thing and trigger the > oom-killer. This change avoids only that particular issue. How does it avoid that? > Agree, its not the actual problem at all. If the core dumping fails, that > sometimes prevents or delays looking into the actual issue. > The sysctl was to allow disabling this behavior or to fine tune for special > cases such as limited memory environments. Please note that any sysctl is an userspace API that has to be maintained effectivelly for ever so there should be a very good reason and a strong justification to add one. I do not see that to be case here. -- Michal Hocko SUSE Labs
